Field of the Invention
The present invention relates to a display device, and more particularly, to a flexible display device with a reduced bezel width and a method of manufacturing the same.
Discussion of the Related Art
Generally, in flexible display devices, a plurality of pixels are formed on a thin and flexible substrate such as plastic, and thus, even when the flexible display devices are folded or rolled up as in paper, the flexible display devices can display a desired image. Therefore, the flexible display devices are attracting much attention as the next-generation display devices, and research and development thereof are being done. Examples of such flexible display devices include flexible liquid crystal display devices, flexible plasma display devices, flexible organic light emitting display devices, flexible electrophoretic display devices, flexible electro-wetting display devices, etc.
FIG. 1 is a cross-sectional view schematically illustrating a general flexible display device.
Referring to FIG. 1, the general flexible display device includes a display panel 10 and a panel driver 20. The display panel 10 includes a lower substrate 12 and an upper substrate 14 which face each other and are coupled to each other.
The lower substrate 12 is formed as a thin and flexible substrate with a material such as plastic. The lower substrate 12 includes a display area that includes a plurality of pixels for displaying an image, a peripheral area that surrounds the display area, and a pad part that is provided in a peripheral area of one side of the lower substrate 12.
For example, a plurality of gate lines and a plurality of data lines that define a plurality of pixel areas are formed to intersect each other in the display area, a thin film transistor (TFT) is formed in each area defined by the intersection of a corresponding gate line and data line, and a pixel electrode connected to the corresponding TFT is formed in each of the pixel areas. The pad part is provided in the peripheral area of the one side of the lower substrate 12 to be connected to the gate lines and the data lines, and is connected to the panel driver 20.
The upper substrate 14 is formed as a thin and transparent substrate with a material such as plastic, and is formed to have an area relatively smaller than the area of the lower substrate 12. The upper substrate 14 faces and is coupled to a portion of the lower substrate 12, except for the pad part of the lower substrate 12 by a coupling member (not shown), which is formed in a closed-loop type, in a non-display area of the lower substrate 12.
An optical film (not shown) may be adhered to a top of the upper substrate 14, in which case the optical film may have an anti-reflection function that prevents polarization and/or reflection of external light.
The panel driver 20 is connected to the pad part of the lower substrate 12, and supplies signals to the gate lines and data lines. To this end, the panel driver 20 may include a flexible circuit board 21, a driving integrated circuit (IC) 23, a control board 25, and a driving circuit part 27.
The flexible circuit board 21 is adhered to the pad part of the lower substrate 12, and bent to be positioned below a bottom area of the lower substrate 12 to surround a side surface of the lower substrate 12.
The driving IC 23 is mounted on the flexible circuit board 21. The driving IC 23 generates data signals and a pixel driving signal for displaying an image on the display panel 10 on the basis of image data and a timing sync signal which are supplied from the control board 25, and supplies the data signals and the pixel driving signal to the pad part.
The control board 25 is adhered to the flexible circuit board 21, and is disposed below the lower substrate 21. The control board 25 is connected to another control board (not shown) that generates image data and the timing sync signal which correspond to an image to be displayed by the display panel 10, and transfers the image data and timing sync signal, which are supplied from the other control board, to the driving IC 23 through the flexible circuit board 21.
The driving circuit board 27 is mounted on the control board 25, and includes passive elements, such as a resistor, a capacitor, and an inductor, and/or an IC. The driving circuit board 27 generates a voltage necessary to drive the display panel 10 and/or the driving IC 23.
The related art flexible display device drives the pixels of the display panel 10 according to a driving of the panel driver 20, thereby displaying a desired image on the display panel 10.
However, in the related art flexible display device of FIG. 1, the panel driver 20 (more specifically, the flexible circuit board 21) is bent to surround a side surface of the lower substrate 12. Therefore, since a portion of the flexible circuit board 21 and a bending part 21a of the flexible circuit board 21 are disposed outside the side surface of the display panel 10, a bezel width W of the related art flexible display device increases due to one side of the lower substrate 12, the portion of the flexible circuit board 21, and the bending part 21a. 
Moreover, the related art flexible display device has an increased number of elements therein due to the presence of the flexible circuit board 21 and the control board 25, which also causes an increase in the manufacturing cost. Also, a yield rate of the related art flexible display device can be reduced by a bonding defect which is caused by the bonding process of adhering the flexible circuit board 21 to the lower substrate 12 and the bonding process of adhering the control board 25 to the flexible circuit board 21.